The invention relates to an assembly for influencing inking in printing machines and, more particularly, an assembly for controlling automatic influencing of inking in printing machines including an ink density measuring device, a device for comparing nominal values and actual values, at least one electronic computer for linking measured values with adjusted values, and devices for metering ink feed to a printing plate and having ink metering elements with appertaining adjustment and reply devices and indications for the actual position values of the ink metering elements.
German Published Prosecuted Patent Application (DE-AS) 27 28 738 describes a device for controlling and regulating inking in printing machines wherein, by means of a system comprising microcomputers, ink regulation is fully automatically performed but has the drawback that a person was excluded as part of the control system, since he could be subjective in his judgement. In that system, however, valuable technical expertise as well as the asset of experience acquired by the printer possibly over many years thereby becomes completely lost to the printing process because, for the printer, in that system no possibility is provided for taking part in the quality correcting process in the regulating or control cycle of the inking. If, for example, due to a faulty ink density measurement resulting from failure or soiling of the densitometer, or due to the presence of paper dust or lint or due to spotty faults in the inking operation, such as so-called water noses, clumps and the like which cannot be absolutely determined in a spatially limited, automatic ink density measurement process with subsequent fully automatic regulation or control. Therefore, a corrective intervention which is necessary, would not be directly possible in the referenced system. Only in case an adjustment command had not been duly performed, are deviations from the correct ink feed subsequently determined by means of renewed or repeated comparison of the nominal positions of the ink metering elements with the actual positions thereof. In such cases the deviations, only if they exceed a given amount, would generate a warning signal which would signal the printer, that a fault had occurred, for example, that a partial section of an inking knife had remained hanging, or that a set screw had become "stuck" or that a servomotor had burned out. In the referenced system, manual control of the ink feed control members is not possible, and therefore signalling of fault sources causes a completely unnecessary time delay in optimization of the ink feed with resulting waste of paper in spite of the fully automatic regulation, and the ink quality of the printed product may be impaired. Nevertheless, a printing machine operator must still be present in order to respond to machine failures and alarm signals.
In contrast therewith, it has been proposed heretofore in German Published Prosecuted Patent Application (DE-AS) 27 27 426 to provide a device which affords a degree of controlled human intervention for regulating or controlling ink feed for a sheet-fed offset printing machine. The device comprises a display device for displaying ink density values and their deviation from values measured previously on the printed product. In the latter system the ink density deviations of all the inking zones are accordingly simultaneously presented as a continuous deviation profile for the entire width of the printed product. The printer is thereby alerted beforehand, as a recommendation, by indirect reference values regarding the amount and the direction of the adJustment to be performed, due to which he is oriented in regard to the adjustment of the inking zone adjusting members, and sufficient room remains for his personal value judgment regarding the quality of the printed product based on visual examination. He then can optimize and regulate the inking and compensate for faults which may not have been be found by measurement techniques. Deviations are, of course, indicated in ink density values, and control thereof, such an adjustment and follow-up of the inking zone adjustment members may be done to the desired extent in accordance with the displayed recommendations and need only be determined again after the next ink density measurement of a sheet taken from the machine, whereby a moderate waste of paper cannot be completely eliminated.
Starting from the above described state of the art, it is an object of the invention to provide a device or assembly which also draws the printer intentionally into the process of inking and indicates to the printer concrete adjustment values regarding absolute adJustment of the inking zone adjustment members, both in degree and in direction, without having to give up the advantages of automatic inking control and which directly permits, on the one hand, monitoring of the ink density measurement value as complement to the automatic density measurement and, on the other hand, also makes possible a direct control as early as during the follow-up of the inking zone adjustment members in accordance with previously introduced position nominal values, in other words, provides total monitoring of the performance of the adjustment commands, not only quantitatively but also qualitatively.
It is another object of the invention to provide a device which permits the printer to exercise exact control of the ink distribution by means of the preceding ink density measurement and to identify and exclude improbable extreme measuring values and which permits repeated measurements.
It is a further object of the invention to provide a device which affords direct control of the ink quality of the printed product without requiring additional expense for construction thereof.
In accordance with an added object of the invention, a device is provided which affords direct control of adjustment deviation even during follow-up of the adjustment of the inking zone adjustment members with respect to desired inking distribution values by means of displayed recommendations.
In accordance with an added object of the invention, possibly remaining simple position-deviations of the inking zone adjustment members as a result of improper performance of the previous adjustment commands are signalled completely without need for further ink density measurements in order to enable the printer to perform direct correction intervention in the inking process.
It is accordingly yet another important object of the invention to provide a device wherein the printer is permitted freedom to decide whether to select automatically regulated, one-time control or manually remotely controlled follow-up of the inking zone adjustment members.
It is also an object of the invention to provide a device wherein individual or several inking zone adjustment members of individual or several printing units may be removed intentionally from automatic follow-up and to perform this adjustment manually and separately.
With the foregoing and other objects in view, there is provided, in accordance with the invention, an assembly for influencing the inking process in printing machines which includes an ink density measurement device, and which also includes a device for comparing desired nominal values and actual measured values, at least one electronic computer for linking the measured values with adjustment values, devices for metering ink feed zonewise to a printing plate and having ink metering elements with appertaining adjustment members and reply devices, including a plurality of visual display indicators assigned to the ink metering elements for providing visual indications for adjustment values of all inking zone adjustment members, respectively, of a printing unit, the indications providing exact recommendations to an operator of the assembly, before adjustment of the inking zone adjustment members, for adJusting the adjustment members to predetermined position values and signaling to the operator absolute adjustment travel thereof both in degree and direction, and a positioning device having means selectable by the operator for following-up the inking zone adjustment members individually of at least one printing unit, the positioning device being coupled with the visual indicators.
Such a device ensures the fastest possible ink optimization for the printed product with a minimum of wasted paper, because the adjustments, already converted into absolute adJustment increments for the inking zone adjustment members, are precisely displayed prior to the follow-up. Although the printer does not have to operate without the advantages of an automatic ink regulation, he always has the possibility of manual intervention and thereby contributing his experience to the printing process.
In order to permit direct control of the ink quality of the printed product without any additional constructional expense, there is provided, in accordance with another feature of the invention, at least one of the sets of first and second indications which is selectively switchable to a set of third indications of ink density trend, the same indicators being provided for all of the first, second and third indications.
In accordance with a further feature of the invention, additional visual indications are provided for indicating the required adjustment increments of the inking zone adjusting members. Direct visual display of the adjustment increments only are required for direct monitoring and absolute control of the inking zone adjustment members that may be needed as a result of incomplete performance of previous adjustment commands.
In accordance with an added feature of the invention, a common reference line is formed by the light elements of the visual display, and wherein values for nominal positions of the inking zone adjustment members are displayed in reference to the common reference line, and which also includes a follow-up profile along a line formed by respective light elements, representing actual positions of the inking zone adjustment members and being position deviations from respective values of the nominal positions on the common reference line. Thereby, both the position deviations of the inking zone adjustment members to the previously given nominal positions as well as possibly remaining position deviations due to incomplete follow-up of the adjustment commands are signaled exactly with respect to amount and direction, which, in turn, permits immediate correction in the inking, completely independent of further ink density measurements.
In accordance with an additional feature of the invention, the ink density measuring device includes a device for releasing the measured values and for transmitting both ink density measurement data, after checking and acceptance by the operator, as well as previously introduced nominal ink density values, to the positioning device, and wherein the device for releasing the measured values is coupled with an enabling switch which is rendered non-enabling after each ink density measurement and before the inking is influenced, and wherein the positioning device has a follow-up control which is part of an automatic follow-up system which is selectively controllable via a selection keyboard, and has a manual remote control, selection of follow-up control which additionally requires a command input by the operator. This gives the printer exact control of the results of the preceding ink density measurement and permits the separation or exclusion of improbable, extreme measurement values as well as the ability to perform repeated measurements.
In accordance with yet another feature of the invention, the positioning device includes a follow-up control for following up one time and an automatic follow-up system for continuously, automatically following up the inking zone adjusting members, and which includes a remote control that is functionally superior to the follow-up control and the automatic follow-up system with manually following up-and correcting the inking zone adjusting members at any time, and which further includes a device for selectively blocking and releasing inking zones by means of the respective inking zone adjustment members of at least one printing unit which may be deliberately removed from and again released to the follow-up control and the automatic follow-up system, respectively, and wherein the manual follow-up by means of the remote control has been maintained. Thus, individual or several inking zone adjustment members in individual or in a plurality of printing units can be removed intentionally from the follow-up and the follow-up can be performed separately and manually, if desired, taking into account locally occurring spatially limited faults in the ink quality which are not always determinable through an ink density measurement on a printing control strip.
In accordance with another feature of the invention there is provided a set of first indications of nominal position values of the ink metering elements that are selectively switchable to a set of second indications that show the adjustment values of all combined inking zone adjustment members, which include a plurality of indicators and in which the same indicator provide for each inking zone both the set of nominal position values and the set of adjustment values.
In accordance with a further feature of the invention there is provided a separate numerical display having its own adjusting keyboard for providing an indication representing adjustment values of an inking zone adjusting member for adjusting the entire ink quantity.
In accordance with an additional feature of the invention, the indicator includes lighting elements for indicating the adjustment displacements of the inking zone adjusting members.
In accordance with an added feature of the invention, there is provided a decentralized microcomputer system with multiple equally ranked microcomputers for computing all measurements necessary for influencing the inking.
In accordance with yet another feature of the invention there is provided a central microcomputer system with at least one hierarchically superior central microcomputer computing all measurements necessary for influencing the inking.
In accordance with a concomitant feature of the invention, the ink density measurement device is a central unit and is coupled simultaneously with follow-up indications and positioning devices of a plurality of printing machines for transmitting values for the purpose of operating at least two of the printing machines, separate follow-up indicators with an appertaining positioning device being assigned- to each of the printing machine units.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in an electronic assembly for influencing inking in printing machines, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.